I have text box.
Users can enter Student Id into that.
Student id is in this format DIP0001.
First three letters should be DIP and the remaining 4 digits should be numeric and can only upto 4 characters.
So how can I check whether entered data is in this format using javascript.
Please help.....
You could build a regular expression pattern and test it against that value to see if it matches that exact pattern.
HTML FILE:
<!DOCTYPE html>
<html lang="en">
<head>
<title>Title</title>
</head>
<body>
<label for="studentId">Student ID</label>
<input id="studentId" type="text">
<button id="btn" type="button">Validate</button>
// Embedded script so that you don't have to load an external file
<script>
var input = document.getElementById('studentId');
var btn = document.getElementById('btn');
var pattern = /DIP+\d{1,3}/g;
btn.addEventListener('click', function(){
if(pattern.test(input.value)) {
alert('It enter code here`atches!');
}else {
alert('It does not match!');
}
});
</script>
</body>
</html>
JS FILE:
// This pattern looks something like this: DIP0000
var pattern = /DIP+\d{1,3}/g;
// studentId is the ID of the input field that contains the Student ID
var studentIdInput = document.getElementById('studentId');
// Check the pattern against the provided Student ID
if(pattern.test(studentIdInput.value)) {
alert('It matches the pattern!');
}
EDIT 1: I have built the functionality in the following JSFiddle: http://jsfiddle.net/vldzamfirescu/QBNrW/
Hope it helps!
EDIT2: I have updated the JSFiddle to match any other combinations up to 4 digits; check it out: http://jsfiddle.net/vldzamfirescu/QBNrW/1/ Let me know if it solved your problem!
try this code
<html>
<head>
<script>
function validate(val) {
if (val.value != "") {
var filter = /^[DIP]|[dip]+[\d]{1,4}$/
if (filter.test(val.value)) { return (true); }
else { alert("Please enter currect Student Id"); }
val.focus();
return false;
}
}
</script>
</head>
<body>
<input id="Text1" type="text" onblur="return validate(this);" />
</body>
</html>
Use Regular Expresions.
If found a valid Student ID, the pattern will return true:
function validateStudentId(id) {
var re = /DIP[0-9]{4}/;
return re.test(id);
}
// Edited for use with a click event:
document.getElementById('button').addEventListener('click', function(){
if( validateStudentId(document.getElementById('textBox').value) ){
alert('correct');
}else{
alert('invalid ID');
}
});
Related
How can I prevent submision if in my text field are entered just specific characters <>{} and not all of special characters? I'm losing my mind :/
I think you are looking for regex expression. Let me know if it's helpful
$(":input").each(function() {
var input = $(this).val();
var regex = new RegExp("^[a-zA-Z]+$");
if(regex.test(input)) {
alert("true");
} else {
alert("false");
return false;
}
})
I don't have an exact answer as you didn't post any sample code. I can only point you to this article https://javascript.info/bubbling-and-capturing which explain how events bubbling works. A solution will be to use event.stopPropagation() in case the validation doesn't pass.
Here an working ex:
<!DOCTYPE html>
<html>
<head>
<script>
function validateForm() {
const regex = new RegExp('^[a-zA-Z]+$');
const input = document.forms['someForm']['somename'].value;
if (regex.test(input)) {
console.log("true");
} else {
console.log("false");
return false;
}
}
</script>
</head>
<body>
<form name="someForm" onsubmit="return validateForm()" method="post">
Name: <input type="text" name="somename">
<input type="submit" value="Submit">
</form>
</body>
</html>
I am currently trying to create a very simple validation script with JS. Basically, I want a alert to come up if the text inputted into a form is shorter than 5 characters, or longer than 25.
<!doctype html>
<html>
<head>
<title>Password Validator</title>
</head>
<body>
<script>
function validate()
{
var yourpw = document.forms.passwordform.yourpassword.length;
if (yourpw < 5);
{
alert("password is too short");
return false;
}
if (yourpw > 25)
{
alert("your password is too long")
return false;
}
}
</script>
<h1>Password Validator</h1>
<p>Please create a new password below</p>
<p>Be sure you password follows these guidelines</p>
<ul>
<li>No shorter than 5 characters</li>
<li>No longer than 25 characters</li>
</ul>
<br>
<form name="passwordform" method="post" onsubmit="validate();">
<input type="text" name="yourpassword">
<br>
<input type="submit">
</form>
</body>
</html>
I am not sure what exactly I am missing or why it wont work but the goal of what i want is that when text is inputted into the text box named "yourpassword", a script will run that will show a message if either one of these conditions are met: shorter than 5 characters, or longer than 25, warning the person typing that their password does not follow the guidelines, if the password meets the guidelines, then i just want a simple confirmation message to appear. Anyways i appreciate any help as this is frustrating me and making me want to give up learning JS. Thanks
you need to first prevent the default behavour of form submit .
use
function validate(e)
{
e.preventDefault();
var yourpw = document.forms.passwordform.yourpassword.value.length;
... rest of code
}
Try updating your validate function to as follows:
function validate(e) {
e.preventDefault();
var yourpw = document.getElementsByName('yourpassword')[0].value.length;
if (yourpw < 5) {
alert("password is too short");
return false;
}
if (yourpw > 25) {
alert("your password is too long")
return false;
}
}
You need to grab the input fields value, as mentioned, the input field does not have a length (#Xufox) as well as prevent the default behavior for form submission.
Edit:
Full working example:
<!doctype html>
<html>
<head>
<title>Password Validator</title>
</head>
<body>
<script>
function validate(e) {
e.preventDefault();
var yourpw = document.getElementsByName('yourpassword')[0].value.length;
if (yourpw < 5); {
alert("password is too short");
return false;
}
if (yourpw > 25) {
alert("your password is too long")
return false;
}
}
</script>
<h1>Password Validator</h1>
<p>Please create a new password below</p>
<p>Be sure you password follows these guidelines</p>
<ul>
<li>No shorter than 5 characters</li>
<li>No longer than 25 characters</li>
</ul>
<br>
<form name="passwordform" method="post" onsubmit="validate(event);">
<input type="text" name="yourpassword">
<br>
<input type="submit">
</form>
</body>
</html>
Use this : but give id name yourpassword to input field .. So you can take the value easily
var yourpw = document.getElementById("yourpassword").value;
var len = yourpw.length;
If ( len < 5 )
{
alert ("this is short");
}
elseif(len>25)
{
alert(" too long")
}
else
{
//// your code
}
You can easily validate forms via RegExp.
use this function for validate 5 character limit.
var pw = document.getElementById("yourpassword").value;
function isValidatePW(PW){
var pwRegExp - /\d{5}/
return pwRegExp.test(PW);
}
I have a very simple HTML/JavaScript form that I am working on for coursework, I have got it to work however i would like it to validate the input as the user types (my validation appears below the text field) how can I achieve this? My code is as follows:
<!DOCTYPE html>
<html>
<head>
<script class="jsbin" src="http:ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"> </script>
<meta charset=utf-8 />
<title>Email Validation</title>
</head>
<body>
<form onsubmit='validate(); return false;'>
<p>Enter an email address:</p>
<input id='email' placeholder="example#example.com" size="21">
<button type='submit' id='validate'>Submit</button>
</form>
<br />
<h2 id='result'></h2>
<script>
function validateEmail(email) {
var re = /^(([^<>()[\]\\.,;:\s#\"]+(\.[^<>()[\]\\.,;:\s#\"]+)*)|(\".+\"))#((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
return re.test(email);
}
function validate() {
$("#result").text("");
var email = $("#email").val();
if (validateEmail(email)) {
$("#result").text(email + " is valid");
$("#result").css("color", "green");
} else {
$("#result").text(email + " is not valid");
$("#result").css("color", "red");
}
return false;
}
$("form").bind("submit", validate);
</script>
</body>
</html>
For methods not using jQuery, in case you're interested, there's another Stack Overflow question here: On Input Change Event.
There are many ways to do what you want listed there, but in this case you could do something like this:
var input = document.querySelector('input');
input.addEventListener('input', function()
{
// Check input.value for what you're looking for here
});
See the jsFiddle that Drew Noakes' made in that other page for an example.
But, since you're using jQuery, then Nicholas Kyriakides's suggestion is the way to go.
I am trying to create a simple HTML program that will allow the user to input a number or word, then if the userInput matches what I have defined, it changes that input to something else, then outputs the new value on the screen.
Also looking for a button to reset the program (at any time to start over)
Any ideas?
<!DOCTYPE html>
<html>
<body>
<h1>Value Converter</h1>
<input type="text" id="userInput"=>Enter the Value</input>
<button onclick="test()">Submit</button>
<script>
function test() {
var userInput = document.getElementById("userInput").value;
//Need to add If, else if, else to change the value of userInput
// for example, If xxxx value, set to yyyy, then output yyyy
document.write(userInput);
}
// Need to add a "reset" to go back to restart the program
</script>
</body>
</html>
Working better now with... but where does the reset go? How do I format the output? all noob questions yes
<!DOCTYPE html>
<html>
<body>
<h1>Value Converter</h1>
<input type="text" id="userInput"=>Enter the Value</input>
<button onclick="test()">Submit</button>
<script>
function test()
{
var userInput = document.getElementById("userInput").value;
if(userInput == "xxxx") {
userInput="yyyy";
}
else if(userInput == "yyyy") {
userInput="zzzz";
}
else {
userInput="Not Found";
}
document.write(userInput);
}
// Need to add a "reset" to go back to restart the program
</script>
</body>
</html>
Convert the function to the following.
function test()
{
var userInput = document.getElementById("userInput").value;
if(userInput == "xxxx") {
// I forgot the updating part here.
document.getElementById("otherIdToWriteOutput").innerHTML = "yyyy";
}
}
You can also add the reset button. And remove the current text using
document.getElementById("id").innerHTML = ""; // remove the inner html.
My following JavaScript is not working:
<script type="text/javascript">
function checkDetails(search)
{
var search = documment.getElementById('query');
if(search.value ==''||search.value==null)
{
alert('No search criteria entered');
query.focus;
return false;
}
}
</script>
</head>
<body>
<form name="search" action ="123.php" onSubmit="return checkDetails(this);" method ="get">
<p><input type ="text" id = "query" name ="query" />
<input type ="submit" value ="Web Service"/></p>
</form>
</body>
Try this code:
function checkDetails(search)
{
var search = document.getElementById('query');
if(search.value ===''||search.value===null)
{
alert('No search criteria entered');
search.focus();
return false;
}
return true;
}
You wrote documment.
You don't specify in what way it's not working - you get an error, it doesn't validate correctly, you don't get the error alert? One thing I spotted:
query.focus;
Should be
search.focus();
Also you misspelled document as documment
Also try something like this
onSubmit="return checkDetails(this,this.id);"
function checkDetails(search,id)
{
var search = documment.getElementById(id);
if(search.value ==''||search.value==null)
{
alert('No search criteria entered');
query.focus;
return false;
}
}
It will be
search.focus();
instead of
query.focus;
and documment will be document